Loss of T12 Sensor Signal through the Two Channels on Engine 1
TASK 73-20-00-810-859-A
Loss of T12 Sensor Signal through the Two Channels on Engine 1
1. Possible Causes
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Referenced Information
3. Fault Confirmation
Subtask 73-20-00-710-134-A ** ON A/C NOT FOR ALL
Subtask 73-20-00-810-109-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:35:22 UTC
Loss of T12 Sensor Signal through the Two Channels on Engine 1
1. Possible Causes
- ECU [4000KS]
- harness J9
- harness J10
- engine 1 T12 temperature sensor
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | BRUSH - BRISTLED |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP2011) | stoddard solvent |
| REFERENCE | DESIGNATION |
|---|---|
| AMM 73-21-40-000-001 | Removal of the T12 Temperature Sensor |
| AMM 73-21-40-000-040 | Removal of the T12 Temperature Sensor |
| AMM 73-21-40-400-001 | Installation of the T12 Temperature Sensor |
| AMM 73-21-40-400-040 | Installation of the T12 Temperature Sensor |
| AMM 73-21-50-000-008 | Removal of the J9 Harness |
| AMM 73-21-50-000-009 | Removal of the J10 Harness |
| AMM 73-21-50-000-042 | Removal of the HJ9 Harness for SAC Engines |
| AMM 73-21-50-000-043 | Removal of the HJ10 Harness for SAC Engines |
| AMM 73-21-50-210-001 | Visual Inspection of the Wiring Harness |
| AMM 73-21-50-210-002 | Visual Inspection of the Wiring Harnesses |
| AMM 73-21-50-400-008 | Installation of the J9 Harness |
| AMM 73-21-50-400-009 | Installation of the J10 Harness |
| AMM 73-21-50-400-042 | Installation of the HJ9 Harness for SAC Engines |
| AMM 73-21-50-400-043 | Installation of the HJ10 Harness for SAC Engines |
| AMM 73-21-60-000-001 | Removal of the Electronic Control Unit (ECU) |
| AMM 73-21-60-400-001 | Installation of the Electronic Control Unit (ECU) |
| ASM 732518 | |
| AMM 73-29-00-710-040 | Operational Test of the FADEC on the ground (with Engine Motoring) |
Subtask 73-20-00-710-134-A ** ON A/C NOT FOR ALL
A. Do the operational test of the FADEC 1A and 1B on the ground (with engine non motoring) AMM 73-29-00-710-040.
4. Fault IsolationSubtask 73-20-00-810-109-A ** ON A/C NOT FOR ALL
A. If the test gives the maintenance messages T12 SENS, J9, ECU + T12 SENS, J10, ECU:
Subtask 73-20-00-810-109-B ** ON A/C NOT FOR ALL - do a check for open or short to ground at pins J9 and J10/7, 18, 19 to pins J9 and J10/1, 2, 3 of the harnesses J9 and J10 between the ECU (4000KS) and the T12 sensor, ASM 732518.
- repair the defective harness J9 or J10.
- disconnect the harnesses J9 and J10 from the ECU (4000KS).
- do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
- if you find damage, repair or replace as required.
- clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
- do a check of the ECU cables resistance between:
. pins 18 and 19 (160 to 250 Ohms)
. pins 18 and 7 (> 10 Megohms)
. pin 18 and the ground (> 10 Megohms).
- replace the ECU [4000KS] AMM 73-21-60-000-001 AMM 73-21-60-400-001.
- disconnect the harnesses J9 and J10 from the T12 sensor.
- do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
- if you find damage, repair or replace as required.
- clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
- do a check of the T12 sensor resistance between:
. pins 1 and 2 (160 to 250 Ohms)
. pin 1 and the ground (> 10 Megohms).
- replace the defective harness J9 AMM 73-21-50-000-008 AMM 73-21-50-400-008 or replace the defective harness J10 AMM 73-21-50-000-009 AMM 73-21-50-400-009.
- replace the engine 1 T12 temperature sensor AMM 73-21-40-000-040 AMM 73-21-40-400-040.
A. If the test gives the maintenance messages T12 SNSR, J9, ECU + T12 SNSR, J10, ECU:
Subtask 73-20-00-810-109-C ** ON A/C NOT FOR ALL - do a check for open or short to ground at pins J9 and J10/7, 18, 19 to pins J9 and J10/1, 2, 3 of the harnesses J9 and J10 between the ECU (4000KS) and the T12 sensor, ASM 732518.
- repair the defective harness J9 or J10.
- disconnect the harnesses J9 and J10 from the ECU (4000KS).
- do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
- if you find damage, repair or replace as required.
- clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
- do a check of the ECU cables resistance between:
. pins 18 and 19 (160 to 250 Ohms)
. pins 18 and 7 (> 10 Megohms)
. pin 18 and the ground (> 10 Megohms).
- replace the ECU [4000KS] AMM 73-21-60-000-001 AMM 73-21-60-400-001.
- disconnect the harnesses J9 and J10 from the T12 sensor.
- do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
- if you find damage, repair or replace as required.
- clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
- do a check of the T12 sensor resistance between:
. pins 1 and 2 (160 to 250 Ohms)
. pin 1 and the ground (> 10 Megohms).
- replace the defective harness J9 AMM 73-21-50-000-008 AMM 73-21-50-400-008 or replace the defective harness J10 AMM 73-21-50-000-009 AMM 73-21-50-400-009.
- replace the engine 1 T12 temperature sensor AMM 73-21-40-000-040 AMM 73-21-40-400-040.
A. If the test gives the maintenance messages T12 SNSR, J9, ECU + T12 SNSR, J10, ECU:
Subtask 73-20-00-710-135-A ** ON A/C NOT FOR ALL - do a check for open or short to ground at pins J9 and J10/7, 18, 19 to pins J9 and J10/1, 2, 3 of the harnesses J9 and J10 between the ECU (4000KS) and the T12 sensor, ASM 732518.
- repair the defective harness J9 or J10.
- disconnect the harnesses J9 and J10 from the ECU (4000KS).
- do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
- if you find damage, repair or replace as required.
- clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-002.
- do a check of the ECU cables resistance between:
. pins 18 and 19 (160 to 250 Ohms)
. pins 18 and 7 (> 10 Megohms)
. pin 18 and the ground (> 10 Megohms).
- replace the ECU [4000KS] AMM 73-21-60-000-001 AMM 73-21-60-400-001.
- disconnect the harnesses J9 and J10 from the T12 sensor.
- do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
- if you find damage, repair or replace as required.
- clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-002.
- do a check of the T12 sensor resistance between:
. pins 1 and 2 (160 to 250 Ohms)
. pin 1 and the ground (> 10 Megohms).
- replace the defective harness J9 AMM 73-21-50-000-042 AMM 73-21-50-400-042 or replace the defective harness J10 AMM 73-21-50-000-043 AMM 73-21-50-400-043.
- replace the engine 1 T12 temperature sensor AMM 73-21-40-000-001 AMM 73-21-40-400-001.
B. Do the test given in Para. 3.A.